Introduction

Hypogeococcus pungens is native to South America and was described by Granara de Willink (1981). A previous description by Williams (1973) classified H. pungens incorrectly as Hypogeococcus festerianus (Lizer y Trelles), and this confusion resulted in numerous publications listing H. pungens as H. festerianus. Little biological information is available for either species, but much of the available literature for H. festerianus actually is H. pungens information.

Figure 1.

Infestation of the mealybug, Hypogeococcus pungens Granara de Willink.

Field specimens of H. pungens are sometimes confused with the pink hibiscus mealybug, Maconellicoccus hirsutus (Green), but the potential hosts of H. pungens are more restrictive. The only other species of Hypogeococcus that occurs in Florida is the native Hypogeococcus margaretae Miller. The only known host for Hypogeococcus margaretae is the hatpin plant, Eriocaulon decangulare, and it has only been reported from St. Lucie and Indian River Counties in Florida.

Synonymy

A related species, H. festerianus is a valid species, but H. pungens has been misidentified as H. festerianus in the following publications: Hamon (1984), McFadyen and Tomley (1981), Suss and Trematerra (1986), and Williams (1973).

Details of these misidentifications are available on ScaleNet with a Hypogeococcus pungens valid name query.

Distribution

This mealybug has been reported from Australia, South America, the Caribbean, Europe, and North America. The Australian populations are the result of introduction for the biological control of cacti. Reports of H. pungens in the U.S. include Florida (1984) and Hawaii (2005).

Identification Characteristics

Adult females are approximately 3 mm long (0.12 inches), produce a reddish body fluid when pierced, and lack both lateral filaments and an ovisac. Hypogeococcus pungens produce large amounts of wax and often form feeding clusters at nodal regions of host plants. The body shape is oval to round, and more round than other pinkish-colored mealybugs (Hodges et. al. 2008).

In Florida, heavy infestations of pink-colored mealybugs on Portulaca and Alternathera species are frequently identified as H. pungens. This species is rarely found on cacti in Florida.

Figure 2.

Shown infesting cacti is Hypogeococcus spinosus Ferris, which is not established in Florida. This species is related to Hypogeococcus pungens Granara de Willink.

Prior to confirming a diagnosis, scale and mealybug insects (Hemiptera: Coccoidea) generally must be slide-mounted. One of the unique morphological characteristics about H. pungens is the presence of three circuli (Miller et. al. 2007, Williams and Willink 1992). The circulus, a structure on the ventral surface of mealybugs, is thought to serve an adhesive function for the insect. Hypogeococcus festerianus, the species originally confused with H. pungens, has only one circulus. Also, the pink hibiscus mealybug and H. margaretae have only one circulus.

Life Cycle

Very little biological or life history information is available specifically for this species. The primary available biological work is Suss and Trematerra (1986). Populations of H. pungens were found both on roots and host leaves or stems. Miller et. al. (2007) also report that H. pungens has been intercepted on the roots of Cactaceae.

Hosts

In comparison to other mealybug species, the host range for H. pungens is fairly limited.

Economic Importance

Hypogeococcus pungens has a very limited host range and appears to be of little economic significance as a pest. Significant pest populations of H. pungens rarely occur in Florida. Although H. pungens was reported occurring on Cactaceae in Italy, subsequent surveys have reported reduced populations (Longo 2009). Exceptions to the general non-pest status of H. pungens could occur in areas with rare or endemic Cactaceae hosts, particularly those that reproduce primarily by seeds instead of budding.

Due to its fairly limited host range, H. pungens was successfully introduced as a biological control agent for the cacti species Eriocereus bonplandii, E. martini, E. tortuosus, and Acanthocereus pentago in Australia (McFadyen and Tomley 1981). This species has also been introduced into South Africa for the control of E. martini (Moran and Zimmermann 1991). Hypogeococcus pungens may be a more effective biological control agent for cacti species that are primarily dependent upon seeds for reproduction. Moran and Zimmerman (1991) noted that the inhibition of flowering and fruiting by E. martini due to H. pungens limited spread of the pest weed. Although H. pungens was a successfully biological control agent for pest weeds in Australia and South Africa, limited natural dispersal abilities of H. pungens require constant reintroduction of the mealybug as new infestations of the cacti weed occur.

Management

For high populations of H. pungens, it is often important to confirm the identification of your species prior to implementing a management strategy. This species may be confused with other similar mealybugs, and it is particularly important to report and submit unusual damage in terms of pest frequency or host range to your local diagnostic lab.

The following identification resources are available for Florida residents:

For many mealybug species, natural enemies will often effectively manage populations. The mealybug destroyer, Cryptolaemus montrouzieri, is commonly found in association with many mealybug species as a generalist predator. Moran and Zimmermann (1991) report the presence of a ladybird beetle, Exochomus sp. (Coleoptera: Coccinellidae) feeding on H. pungens, but detailed observations on the impact of this species on populations is not provided. For additional information on natural enemies see Beneficial Insects and Mites.

Natural enemy populations will be negatively impacted by any pesticide applications applied to the host for control of H. pungens or other species. Mealybug populations may also be controlled by horticultural oil applications, but natural enemy populations may be adversely impacted by this as well.

Acknowledgements

The authors acknowledge Renato Inserra, FDACS-DPI, for translation of the Suss and Trematerra (1986) manuscript and for communications with Santi Longo, University of Cantania in Sicily, regarding status of H. pungens in Italy.

Footnotes

1.

This document is EENY-459, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: June 2009. Reviewed June 2012. This document is also available on Featured Creatures website at http://entomology.ifas.ufl.edu/creatures. Please visit the EDIS website at http://edis.ifas.ufl.edu. Additional information on these organisms, including many color photographs, is available at the Entomology and Nematology Department website at http://entnemdept.ifas.ufl.edu.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.